The black blazer — almost every girl has it, and celebs are especially obsessed with it. It's a totally versatile style staple that can easily go from work to play with just a quick outfit switch-up. To prove that the black blazer is a style must, we tracked down 25 celebs, some wearing the blazer in an office-appropriate way, and others in a snazzy party style. Step inside to see who's wearing the black blazer and to draw inspiration from their looks for your work life and after-work activities.